Stain-proofing spectacle lens and manufacturing method thereof

ABSTRACT

A spectacle lens that can lower the slipperiness of a lens surface to an extent that allows an edging process by making without deteriorating the stain-proofing performance of the stain-proofing layer, when a stain-proofing layer is formed of two or more kinds of silane compounds including at least one or more kinds of fluorine-containing silane compounds, and as for the dynamic friction coefficient of lens surfaces defined by each of the two or more kinds of silane compounds as a single component, the highest value of the dynamic friction coefficients 1.4 times or more of the lowest value of the dynamic friction coefficients; and a manufacturing method thereof are provided.

TECHNICAL FIELD

The present invention relates to a stain-proofing spectacle lens thatcan inhibit a spectacle lens, to which stain-proofing treatment isapplied, from slipping when an edging process is applied and thereby canimprove the processing accuracy without deteriorating excellentstain-proofing performance, and a manufacturing method thereof.

BACKGROUND ART

In a spectacle lens, normally, in order to suppress light from beingreflected and thereby to improve the light transmittance, ananti-reflection coating is formed on a surface thereof. However, whenthe lens is used, there are problems in that stains due to adhesion ofdirt from hand, fingerprint, sweat, cosmetics and so on tend to standout and furthermore these stains are difficult to remove. Accordingly,in order to make the lens difficult to be stained or to make stainseasier to be wiped off, on a surface of the anti-reflection coating, astain-proofing layer is further disposed. A method in which surfacetreatment is applied with a fluorine-containing silane compound that isa surface treatment agent for providing a stain-proofing layer to thespectacle lens is disclosed as a prior art in, for instance, JP-ANo.9-258003.

However, the spectacle lens that is surface-treated with afluorine-containing silane compound in JP-A No.9-258003, beingremarkably small in the friction coefficient in comparison with aconventional surface treatment agent, is very slippery in its surface.Accordingly, there are problems such as follows. That is, at retailer'sshops of the spectacles, a so-called edging process, by which a circularspectacle lens is polished into a shape that can be accommodated in aspectacle frame, is performed. In the edging process, while holding aspectacle lens by a friction force in a method in which an opticalcenter of a spectacle lens is sucked and held by a chuck of an edgingmachine or a method in which the spectacle lens is clipped from bothsides by pressing, an edge of the spectacle lens is ground with agrinding stone. During the edging process, the spectacle lens that issurface-treated with a fluorine-containing silane compound in JP-ANo.9-258003 is slippery in the lens surface held by the chuck;accordingly, during the grinding with the grinding stone, owing to thegrinding pressure of the grinding stone, axis deviation, where a centerof the lens deviates from a center of the chuck, is caused, resulting inincapability of accurately applying the edging process.

Accordingly, the spectacle lenses, to which the stain-proofing processis applied with the fluorine-containing silane compound that isexcellent in the stain-proofing effect, are edged in production plantswhile paying attention not to cause the axis deviation. However, forspectacle lenses that are necessary to be edged at retailer's shops, inorder that an accurate edging process may be applied at the retailer'sshops, ones that are lowered in the surface slipperiness by processingby less-effective stain-proofing treatment are supplied to secure theholding of the spectacle lens.

The present invention was carried out in view of the above situationsand intends to provide a spectacle lens that can be lowered in thesurface slipperiness of a lens surface to an extent that allows applyingthe edging process without deteriorating excellent stain-proofing effectof a stain-proofing layer, and a manufacturing method thereof.

DISCLOSURE OF INVENTION

The present inventors studied hard to achieve the above objects andresultantly found that when a stain-proofing layer is formed of two ormore kinds of silane compounds that are selected so as to be differentin the dynamic friction coefficient of the lens surface after thetreatment and at least one or more kinds of which arefluorine-containing silane compounds, the slipperiness of a lens surfacecan be reduced to an extent that allows applying the edging processwithout deteriorating the stain-proofing effect intrinsic to thefluorine-containing compound.

Furthermore, since there is a problem that stains on an anti-reflectioncoating disposed on a surface of a spectacle lens tend to stand out andare difficult to remove, forming of a stain-proofing layer is effective.

Accordingly, a firstly described invention provides a stain-proofingspectacle lens characterized in that, on a surface of a spectacle lens,a stain-proofing layer is formed of two or more kinds of silanecompounds including at least one or more kinds of fluorine-containingsilane compounds, and as for the dynamic friction coefficients of lenssurfaces, separately defined by each of the two or more kinds of silanecompounds, the highest dynamic friction coefficient is 1.4 times or morethat of the lowest one.

A second invention provides a stain-proofing spectacle lenscharacterized in that, in the stain-proofing spectacle lens according toclaim 1, out of two or more kinds of the silane compounds, a content ofa silane compound, with which a surface having the lowest dynamicfriction coefficient can be obtained, is in the range of 30 to 99%relative to a total amount of silane compounds.

A third invention provides a stain-proofing spectacle lens characterizedin that, in the stain-proofing spectacle lens according to claim 1, thedynamic friction coefficient of a lens surface, defined by a silanecompound that can obtain the surface having the lowest dynamic frictioncoefficient, out of the two or more kinds of silane compounds, is 0.2 orless.

A fourth invention provides a stain-proofing spectacle lenscharacterized in that, in the stain-proofing spectacle lens according tothe first invention, out of the two or more kinds of silane compounds,at least one kind thereof is expressed with a general formula (1) below.

(In the formula, R_(f) expresses a straight chain or a branched chain ofperfluoroalkyl group having 1 to 16 carbon atoms; X, an iodine or ahydrogen atom; Y, a hydrogen atom or a lower alkyl group; Z, a fluorineatom or a trifluoromethyl group; R¹, a hydrolizable group; R², ahydrogen atom or an inactive monovalent organic group; a, b, c and d, aninteger of 0 to 200; e, 0 or 1; m and n, an integer of 0 to 2; and p, aninteger of 1 to 10.).

A fifth invention provides a stain-proofing spectacle lens characterizedin that, in the stain-proofing spectacle lens described in any one ofthe first through fourth inventions, an anti-reflection coating isformed in a lower layer of a stain-proofing layer of the stain-proofingspectacle lens.

A sixth invention provides a method of manufacturing a stain-proofingspectacle lens including a step of forming an anti-reflection coating ona surface of lens base material on which a hard coat film may be formed,and a step of forming a stain-proofing layer from two or more kinds ofsilane compounds, at least one or more kinds of which arefluorine-containing silane compounds, on the antireflection coating;wherein, in the dynamic friction coefficients of lens surfaces, definedseparately by each of two or more kinds of silane compounds, the highestvalue of the dynamic friction coefficient is 1.4 times or more of thelowest value.

A seventh invention provides a method of manufacturing a stain-proofingspectacle lens, in which a treatment agent containing two or more kindsof the silane compounds is coated on a lens surface in the step offorming a stain-proofing layer from two or more kinds of silanecompounds including at least one or more kinds of fluorine-containingsilane compounds on the antireflection coating in the method ofmanufacturing a stain-proofing spectacle lens according to the sixthinvention.

An eighth invention provides a method of manufacturing a stain-proofingspectacle lens in which two kinds or more of the silane compounds areevaporated in a vacuum chamber and deposited on a lens surface in thestep of forming a stain-proofing layer from two or more kinds of silanecompounds including at least one kind or more of fluorine-containingsilane compounds on the antireflection coating in the method ofmanufacturing a stain-proofing spectacle lens according to the sixthinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a manufacturing process diagram of a stain-proofing spectaclelens.

FIG. 2 is a side view showing an example of a chuck that holds a lens ofan edging machine.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of a stain-proofing spectacle lens according tothe present invention and a manufacturing method thereof will beexplained; however, the present invention is not restricted to theembodiments below. As mentioned above, The stain-proofing spectacle lensaccording to the invention can be obtained by forming a stain-proofinglayer from two or more kinds of silane compounds that are selected so asto be different in the dynamic friction coefficient of a lens surfaceafter the treatment and at least one or more kinds of which arefluorine-containing silane compounds.

As for base materials of the spectacle lens, either one of inorganicglass and plastics can be used. As for the plastics, diethylene glycolbisallyl carbonate (CR-39), polyurethane resin, thiourethane resin,polycarbonate resin and acrylic resin can be cited.

In the case of a glass lens, a stain-proofing layer can be directlyformed on the glass lens; however, normally, the stain-proofing layer ispreferably disposed after an anti-reflection coating is applied in thecase of the glass lens, and the stain-proofing layer is preferablydisposed after a hard coat film and an anti-reflection coating areapplied in the case of plastic lens.

The hard coat film endows the plastic lens with the scratch resistance;in addition to the above, since the adhesiveness of the anti-reflectioncoating to the plastic lens is not good in general, the hard coat filmis interposed between the plastic lens and the anti-reflection coatingto improve the adhesiveness of the antireflection coating and thereby toinhibit the anti-reflection coating from peeling off.

As for a method of forming a hard coat film, a method of coating acurable composition that can form a hard coat film on a surface of theplastic lens, and curing a coated film is generally used. In the case ofthe plastic lens being a thermoplastic resin, one that can be cured byelectromagnetic waves such as UV light and ionizing radiation such aselectron beams can be used more preferably than a thermosetting type.For instance, a photo-curable silicone compound mainly made of asilicone compound that generates a silanol group by UV lightirradiation, and organo-polysiloxane having a halogen atom or a reactivegroup such as an amino group that causes a condensation reaction withthe silanol group; an acrylic UV-curable monomer composition such asUK-6074 manufactured by Mitsubishi Rayon Co., Ltd.; and a fine inorganicparticles-containing thermosetting composition, in which fine inorganicparticles such as SiO₂ and TiO₂ having a particle diameter in the rangeof 1 to 100 nm are dispersed in a silane compound or a silane-couplingagent that has a polymerizing group such as a vinyl group, an allylgroup, an acrylic group or a methacrylic group and a hydrolyzing groupsuch as a methoxy group, can be cited.

As for a method of forming a coating, a dipping method, a spin-coatmethod, a spray coating method, a float method and a doctor blade methodcan be adopted.

Prior to the formation of the coating, in order to improve theadhesiveness, a surface of the plastic lens is preferablysurface-treated by means of corona discharge, high voltage discharge ofmicrowaves and so on.

When a formed coating is cured by means of heat, UV light, electron beamand so on, a hard coat film can be obtained.

A film thickness of the hard coat film is preferably in the range ofsubstantially 0.05 to 30 μm. When the film thickness is excessivelythin, the fundamental performance cannot be exhibited in some cases; onthe other hand, when it is excessively thick, optical distortion may becaused in some cases.

The anti-reflection coating is constituted of a single layer or amulti-layer of inorganic coating or organic coating. As for materials ofthe inorganic coating, inorganic substances such as SiO₂, SiO, ZrO₂,TiO₂, TiO, Ti₂O₃, Ti₂O₅, Al₂O₃, Ta₂O₅, CeO₂, MgO, Y₂O₃, SnO₂, MgF₂ andWO₃ can be cited. These can be used singly or in combinations of two ormore kinds. In the case of the plastic lens, SiO₂, ZrO₂, TiO₂ and Ta₂O₅that can be vacuum-vaporized at low temperatures are preferable.Furthermore, in the case of the anti-reflection coating being formedinto a multi-layered structure, the outermost layer is preferably formedof SiO₂.

As a multi-layered film of inorganic coatings, a four layered structurehaving, from the lens side, a ZrO₂ layer and a SiO₂ layer having a totaloptical film thickness of λ/4, a ZrO₂ layer having an optical filmthickness of λ/4 and a SiO₂ layer at the uppermost having a totaloptical film thickness of λ/4 can be cited. Here, λ is a designwavelength and normally 520 nm is used.

As for a deposition method of the inorganic coating, for instance, avacuum deposition method, an ion plating method, a sputtering method, aCVD method and a precipitation method by a chemical reaction in asaturated solution can be adopted.

A material of the organic coating is selected in considering therefractive indices of the plastic lens and the hard coat film, and otherthan the vacuum deposition method, coating methods excellent in the massproduction capability such as a spin coat method and a dip coat methodcan be used to form.

In a stain-proofing spectacle lens according to the invention, on theoutermost surface of the spectacle lens, that is, on the above-mentionedhard coat film or deposition film, a stain-proofing layer is formed, andthe stain-proofing layer can be obtained by forming from two or morekinds of silane compounds that are selected so as to be different in thedynamic friction coefficient of the lens surface after the treatment andinclude at least one or more kinds of fluorine-containing silanecompounds.

By including a fluorine group, the stain-proofing layer, is formed bytreating a spectacle lens surface with a fluorine-containing silanecompound, develops excellent water repellency and oil repellency, andhas stain-proofing characteristics intrinsic to the stain-proofinglayer, that is, performances such as that the contamination preventiveproperties are excellent, the effect thereof can continue, and thecontamination can be easily removed. On the other hand. Because thesurface slipperiness is so significant, when applying an edging processto a spectacle lens by mounting the spectacle lens on the chuck of theedging machine, the polishing pressure of the grinding stone that grindsbecomes overcome the frictionally holding force of the chuck, and insome cases resulting in causing the axis deviation of the spectacle lensduring the edging process. As for the chuck of the edging machine, thereis a method in which a horn-shaped rubber sucking part sucks and holds aspectacle lens and a method in which a spectacle lens is pressed fromboth sides thereof and held.

In order to eliminate the axis deviation, it is necessary to reduce onlythe surface slipperiness to an extent that can make the frictionallyholding force of the chuck of the edging machine larger than thepolishing pressure of the grinding stone without adversely affecting onthe stain-proofing effect intrinsic to the stain-proofing layer; when astain-proofing layer is formed of two or more kinds of silane compoundsthat are selected, as treatment agents that are used in the formation ofthe stain-proofing layer, so as to be different in the dynamic frictioncoefficient of the lens surface after the treatment and at least one ormore kinds of which are fluorine-containing silane compounds, aspectacle lens having the desired stain-proofing properties can beobtained.

The two or more kinds of silane compounds that form a stain-proofinglayer and including at least one or more kinds of fluorine-containingsilane compounds, are selected so that the dynamic friction coefficientsof lens surfaces, formed with each of the two or more kinds of silanecompounds as a single component, may be different each other, and amongthese, as one that can obtain a lens surface having a relatively lowdynamic friction coefficient, a fluorine-containing silane compound thatis expressed by a general formula (1) described below and proposed in,for instance, JP-A No.9-258003 can be preferably used.

In the general formula (1), R_(f) expresses a straight chain or abranched chain perfluoroalkyl group having 1 to 16 carbon atoms andpreferably CF₃—, C₂F₅— and C₃F₇—. R¹ expresses a hydrolizable group andpreferably, for instance, a halogen atom, —OR³, —OCOR³, —OC(R³)═C(R⁴)2,—ON═C(R³)₂, and —ON═CR⁵. More preferable ones are a chlorine atom, —OCH₃and —OC₂H₅. Here, R³ expresses an aliphatic hydrocarbon group or anaromatic hydrocarbon group; R⁴, a hydrogen atom or a lower aliphatichydrocarbon group; and R⁵, a divalent aliphatic hydrocarbon group having3 to 6 carbon atoms. R² expresses a hydrogen atom or an inactivemono-valent organic group and preferably a monovalent hydrocarbon grouphaving 1 to 4 carbon atoms. Each of a, b, c and d expresses an integerof 0 to 200 and preferably 1 to 50, and e is 0 or 1. Each of m and nexpresses an integer of 0 to 2 and preferably 0. P is an integer of 1 ormore and preferably an integer of 1 to 10. Furthermore, a molecularweight is in the range of 5×10² to 1×10⁵ and preferably 5×10² to 1×10⁴.

Still furthermore, as one having a preferable structure of thefluorine-containing silane compounds that are expressed by the generalformula (1), ones expressed by a general formula (2) below can be cited.

In the formula, Y expresses a hydrogen atom or a lower alkyl group; R¹,a hydrolizable group; q, an integer of 1 to 50; m, an integer of 0 to 2;and r, an integer of 1 to 10.

Furthermore, as a trade name, for instance, OPTOOL DSX, manufactured byDaikin Industries, Ltd. and KY-130, manufactured by Shin-Etsu ChemicalCo., Ltd. can be cited.

Subsequently, silane compounds that can obtain a lens surface having arelatively high dynamic friction coefficient include such as3,3,3-trifluoropropyltrimethoxysilane,tridecafluorooctyltrimethoxysilane,heptadecafluorodecyltrimethoxysilane, n-trifluoro (1,1,2,2-tetrahydro)propyl silazane, n-heptafluoro (1,1,2,2-tetrahydro) pentyl silazane,n-nonafluoro (1,1,2,2-tetrahydro) hexyl silazane, n-tridecafluoro(1,1,2,2-tetrahydro) octyl silazane, n-heptadecafluoro(1,1,2,2-tetrahydro) decyl silazane, octadecyltriethoxysilane,octadecyltrimethoxysilane, phenyltriethoxysilane,phenyltrimethoxysilane, heptylmethyldichlorosilane,isobutyltrichlorosilane, octadecylmethyldimethoxysilane andhexamethyldisilazane.

Furthermore, trade names such as KP-801, LS-1090, LS-4875, LS-4480,LS-2750, LS-1640, LS-410, and LS-7150, manufactured by Shin-EtsuChemical Co., Ltd. and TSL-8257, TSL-8233, TSL-8185, TSL-8186, TSL-8183and XC95-A9715, manufactured by GE Toshiba Silicones Co., Ltd. can becited.

Among these silane compounds, silane compounds are preferably selectedso that in values of the dynamic friction coefficient, the highest valueof the dynamic friction coefficients may be 1.4 times or more of thelowest value and more preferably 1.8 times or more. By thusimplementing, without deteriorating the excellent stain-proofingproperties, the surface slipperiness of the lens can be lowered to anextent that allows applying edging process.

When the ratio of the highest value of the dynamic friction coefficientto the lowest value thereof is less than 1.4, the excellentstain-proofing properties can be exhibited; however, since theslipperiness of the lens surface is large, the axis deviation may beunfavorably caused.

Furthermore, in order to secure the excellent stain-proofingperformance, among two or more kinds of silane compounds including atleast one or more kinds of fluorine-containing silane compounds, acontent of a silane compound, which can obtain a surface having a lowestdynamic friction coefficient, is preferably set in the range of 30 to99% by weight of a total amount of silane compounds and more preferablyin the range of 50 to 98% by weight. When a content of a silanecompound, which can obtain a surface having a lowest dynamic frictioncoefficient, is less than 30% by weight relative to a total amount ofthe silane compounds, the stain-proofing performance is unfavorablydeteriorated even though the axis deviation is not caused. On thecontrary, when the content thereof exceeds 99% by weight of a totalamount of silane compounds, the axis deviation is unfavorably likely tobe caused.

A value of the dynamic friction coefficient of a lens surface formedwith a silane compound as a single component, which can obtain a surfacehaving a lowest dynamic friction coefficient, is preferably 0.2 or lessand more preferably 0.15 or less. When the value of the dynamic frictioncoefficient of the lens surface exceeds 0.2, the stain-proofingperformance is unfavorably deteriorated.

Although not particularly restricted, as shown in a manufacturingprocess diagram of FIG. 1, a method of forming a stain-proofing layerincludes a step of forming a stain-proofing layer from two or more kindsof silane compounds including at least one or more kinds offluorine-containing silane compounds.

In forming a stain-proofing layer with two or more kinds of silanecompounds-including at least one or more kinds of fluorine-containingsilane compounds, on a spectacle lens by means of coating, a method ofcoating silane compounds, dissolved in an organic solvent, on a surfaceof the spectacle lens can be adopted. As a coating method, a dippingmethod, a spin coat, a spray method, a flow method, a doctor-blademethod, a roll coat method, a gravure coat method and a curtain flowcoat method can be used. As an organic solvent, perfluorohexane,perfluorocyclobutane, perfluorooctane, perfluorodecane,perfluoromethylcyclohexane, perfluoro-1,3-dimethylcyclohexane,perfluoro-4-methoxybutane, perfluoro-4-ethoxybutane and metaxylenehexafluoride can be cited. Furthermore, perfluoroether oil andchlorotrifluoroethylene oligomer oil can be used. Other than these,chlorofluorocarbon 225 (a mixture of CF₃CF₂CHCl₂ and CClF₂CF₂CHClF) canbe cited. These organic solvents can be used singly or in combinationsof two or more kinds.

A concentration at diluting with an organic solvent is preferably in therange of 0.03 to 1% by weight. When the concentration is excessivelylow, a stain-proofing layer having a sufficient thickness can be hardlyobtained, resulting in, in some cases, being incapable of obtainingsufficient stain-proofing effect; on the other hand, when theconcentration is excessively high, since the stain-proofing layer islikely to be formed excessively thick, it is likely that burden ofrinsing process for removing irregularity after coating increases.

The stain-proofing layer according to the invention reacts at normaltemperature and is fixed on a lens surface; however, as needs arise, itis preferably held under a high temperature and high humidityenvironment to complete the reaction more completely.

As a method of coating silane compounds, a vacuum deposition methodwhere the silane compounds are evaporated in a vacuum chamber to depositon a surface of a spectacle lens can be adopted. In the case of ananti-reflection coating being formed on a lens surface by means of thevacuum deposition method, the stain-proofing layer is preferably formedsuccessively without exposing the lens to air at once. In the vacuumdeposition method, a raw material compound can be used at a highconcentration or without a diluting agent.

Although not particularly restricted, a thickness of the stain-proofinglayer is in the range of 0.001 to 0.5 μm and preferably in the range of0.001 to 0.03 μm. When the thickness of the stain-proofing layer isexcessively thin, the stain-proofing effect becomes unfavorably less; onthe other hand, when it is excessively thick, a surface thereof becomesunfavorably sticky. Furthermore, in the case of the stain-proofing layerbeing formed on a surface of the anti-reflection coating, when thethickness of the stain-proofing layer is thicker than 0.03 μm, theanti-reflection effect is unfavorably deteriorated.

After the stain-proofing layer is formed, treatment for removingunreacted molecules and molecules whose reaction has not come tocompletion may be applied. For instance, an organic solvent that candissolve the silane compounds can be applied for the treatment or analkaline-aqueous solution can be used to for the treatment.

As for an organic solvent, organic compounds having a perfluoro group,excellent in the solubility of the silane compounds, and having 4 ormore carbon atoms, are preferable. For instance, perfluorohexane,perfluorocyclobutane, perfluorooctane, perfluorodecane,perfluoromethylcyclohexane, perfluoro-1,3-dimethylcyclohexane,perfluoro-4-methoxybutane, perfluoro-4-ethoxybutane and metaxylenehexafluoride can be cited. Furthermore, perfluoroether oil andchlorotrifluoroethylene oligomer oil can be used. Other than these,chlorofluorocarbon 225 (a mixture of CF₃CF₂CHCl₂ and CClF₂CF₂CHClF) canbe cited. These organic solvents can be used singly or in combinationsof two or more-kinds.

An alkaline aqueous solution is preferably 9 or more in the pH. As foran alkali source, sodium hydroxide, potassium hydroxide, sodiumcarbonate, potassium carbonate and so on can be cited. In the alkalineaqueous solution, a surfactant can be added to improve the cleaningeffect. As a surfactant that is added to the alkaline aqueous solution,without particularly restricting, anionic surfactants, cationicsurfactants, nonionic surfactants and amphoteric surfactants, siliconebase surfactants and fluorine base surfactants can be used. Furthermore,when in the case of alkali soap or the like being used, and the pH of 9or more can be obtained by the addition of the surfactant componentalone, the alkali source has not to be used.

As for specific examples for anionic surfactants, aliphatic acid salts,alkyl sulfates, alkylbenzene sulfonates, alkyl phosphates andpolyoxyethylene alkyl sulfate esters can be cited; as for cationicsurfactants, alkylammonium salts and alkylamine salts can be cited; andas for nonionic surfactants, polyoxyethylene alkyl ether,polyoxyethylene aliphatic acid ester, oxyethylene-oxypropylene blockcopolymer and glycerin aliphatic acid ester can be cited.

Other than the organic solvents and the alkaline aqueous solution, afluorine base surfactant having, for instance, a perfluoro group, alsocan be used as a direct treatment agent or a surfactant added to anorganic solvent or an alkaline aqueous solution. As for the fluorinebase surfactant, perfluoroalkyl (C₇ to C₂₀) carboxylic acids,perfluoroalkyl (C₄ to C₁₂) sulfonic acids and so on can be cited.

As a method of treating a stain-proofing layer with these agents, amethod of wiping and cleaning with paper or cloth impregnated with anagent or a method of dipping in a bottle (cleaning vessel) containing anagents, followed by oscillating or applying physical energy such asultrasonic wave, can be applied.

Embodiments according to the present application and comparativeexamples will be detailed below.

(Embodiment 1)

In a fluorine base solvent (trade name Novec HFE-7200, manufactured bySumitomo 3M Co.), 0.186% by concentration of solid component of a silanecompound A (trade name KY-130, manufactured by Shin-Etsu Chemical Co.,Ltd.) that gives the dynamic friction coefficient of a lens surface of0.07 when applied thereon as a single component, and 0.014% byconcentration of solid component of a silane compound B (trade nameKP-801, manufactured by Shin-Etsu Chemical Co., Ltd.) that gives thedynamic friction coefficient of a lens surface of 0.34 when appliedthereon as a single component, were diluted, and thereby a solution of0.2% by concentration of solid content was prepared as a treatmentsolution for Dip.

A ratio of the dynamic friction coefficients of the silane compound Aand the silane compound B ((the highest value of dynamic frictioncoefficient)/(the lowest value of dynamic friction coefficient)) was4.9.

As for a lens material, a plastic spectacle lens having a layer of hardcoat film and an anti-reflection coating (the outermost layer is a SiO₂film) (Seiko Super Soverein, manufactured by Seiko Epson Corporation)was prepared and plasma treatment was applied to cleanse a surfacethereof. The plasma treatment was carried out under the conditions oftreatment pressure: 0.1 Torr, introduced gas: dry air, a distancebetween electrodes: 24 cm, output power: DC 1 KV, and a treatment timeperiod: 15 sec.

A plasma-treated lens was immersed in the Dip treatment solution andheld for 1 min, followed by pulling up at 40 cm/min, further followed byputting in a constant temperature and constant humidity chamber set at60 degree centigrade and 60% RH and holding there for 2 hr, and therebya stain-proofing layer was formed.

(Embodiment 2)

In a fluorine base solvent (trade name Novec HFE-7200, manufactured bySumitomo 3M Co.), 0.1% by concentration of solid component of a silanecompound A (trade name KY-130, manufactured by Shin-Etsu Chemical Co.,Ltd.) that gives the dynamic friction coefficient of a lens surface of0.07 when applied thereon as a single component, and 0.1% byconcentration of solid component of a silane compound B (trade nameKP-801, manufactured by Shin-Etsu Chemical Co., Ltd.) that gives thedynamic friction coefficient of a lens surface of 0.34 when appliedthereon as a single component, were diluted, and thereby a solution of0.2% by concentration of solid content was prepared as a treatmentsolution for Dip.

A ratio of the dynamic friction coefficients of the silane compound Aand the silane compound B ((the highest value of dynamic frictioncoefficient)/(the lowest value of dynamic friction coefficient)) was4.9.

As for a lens material, a plastic spectacle lens having a layer of hardcoat film and an antireflection coating (the outermost layer is a SiO₂film) (Seiko Super Soverein, manufactured by Seiko Epson Corporation)was prepared and plasma treatment was applied to cleanse a surfacethereof. The plasma treatment was carried out under the conditions oftreatment pressure: 0.1 Torr, introduced gas: dry air, a distancebetween electrodes: 24 cm, output power: DC 1 KV, and a treatment timeperiod: 15 sec.

A plasma-treated lens was immersed in the Dip treatment solution andheld there for 1 min, followed by pulling up at 40 cm/min, furtherfollowed by putting in a constant temperature and constant humiditychamber set at 60 degree centigrade and 60% RH and holding there for 2hr, and thereby a stain-proofing layer was formed.

(Embodiment 3)

In perfluorohexane, 0.19% by concentration of solid component of asilane compound C (trade name Optool DSX, manufactured by DaikinIndustries Ltd.) that gives the dynamic friction coefficient of a lenssurface of 0.09 when applied thereon as a single component, and 0.01% byconcentration of solid component of a silane compound B (trade nameKP-801, manufactured by Shin-Etsu Chemical Co., Ltd.) that gives thedynamic friction coefficient of a lens surface of 0.34 when appliedthereon as a single component, were diluted, and thereby a solution of0.2% by concentration of solid content was prepared as a treatmentsolution for Dip.

A ratio of the dynamic friction coefficients of the silane compound Cand the silane compound B ((the highest value of dynamic frictioncoefficient)/(the lowest value of dynamic friction coefficient)) was3.8.

As for a lens material, a plastic spectacle lens having a layer of hardcoat film and an anti-reflection coating (the outermost layer is a SiO₂film) (Seiko Super Soverein, manufactured by Seiko Epson Corporation)was prepared and plasma treatment was applied to cleanse a surfacethereof. The plasma treatment was carried out under the conditions oftreatment pressure: 0.1 Torr, introduced gas: dry air, a distancebetween electrodes: 24 cm, output power: DC 1 KV, and a treatment timeperiod: 15 sec.

A plasma-treated lens was immersed in the Dip treatment solution andheld there for 1 min, followed by pulling up at 40 cm/min, furtherfollowed by putting in a constant temperature and constant humiditychamber set at 60-degree centigrade and 60% RH and holding there for 2hr, and thereby a stain-proofing layer was formed.

(Embodiment 4)

In a mixture of perfluorohexane and a fluorine base solvent (trade nameNovec HFE-7200, manufactured by Sumitomo 3M Co.) mixed at a weight ratioof 1/1, 0.19% by concentration of solid component of a silane compound C(trade name Optool DSX, manufactured by Daikin Industries Ltd.) thatgives the dynamic friction coefficient of a lens surface of 0.09 whenapplied thereon as a single component, and 0.01% by concentration ofsolid component of a silane compound D (trade name TSL-8185,manufactured by GE Toshiba Silicones Co., Ltd.) that gives the dynamicfriction coefficient of a lens surface of 0.48 when applied thereon as asingle component, were diluted, and thereby a solution of 0.2% byconcentration of solid content was prepared as a treatment solution forDip.

A ratio of the dynamic friction coefficients of the silane compound Cand the silane compound D ((the highest value of dynamic frictioncoefficient)/(the lowest value of dynamic friction coefficient)) was5.3.

As for a lens material, a plastic spectacle lens with a layer of hardcoat film and an anti-reflection coating (the outermost layer is a SiO₂film) (Seiko Super Soverein, manufactured by Seiko Epson Corporation)was prepared and plasma treatment was applied to cleanse a surfacethereof. The plasma treatment was carried out under the conditions oftreatment pressure: 0.1 Torr, introduced gas: dry air, a distancebetween electrodes: 24 cm, output power: DC 1 KV, and a treatment timeperiod: 15 sec.

A plasma-treated lens was immersed in the Dip treatment solution andheld there for 1 min, followed by pulling up at 40 cm/min, furtherfollowed by putting in a constant temperature and constant humiditychamber set at 60 degree centigrade and 60% RH and holding there for 2hr, and thereby a stain-proofing layer was formed.

After taking out of the constant temperature and constant humiditychamber, and followed by cooling, the lens was attached to a lens fixingjig and immersed in a ultrasonic washing tank filled withperfluorohexane, and the ultrasonic waves were applied to cleanse.Conditions of the ultrasonic washing were bath capacity: 2.6 liter,oscillation frequency: 38 kHz, output power: 120 W and treating timeperiod: 30 sec.

(Embodiment 5)

In a mixture of perfluorohexane and a fluorine base solvent (trade nameNovec HFE-7200, manufactured by Sumitomo 3M Co.) mixed at a weight ratioof 1/1, 0.18% by concentration of solid component of a silane compound C(trade name Optool DSX, manufactured by Daikin Industries Ltd.) thatgives the dynamic friction coefficient of a lens surface of 0.09 whenapplied thereon as a single component, 0.01% by concentration of solidcomponent of a silane compound B (trade name KP-801, manufactured byShin-Etsu Chemical Co., Ltd.) that gives the dynamic frictioncoefficient of a lens surface of 0.34 when applied thereon as a singlecomponent, and 0.01% by concentration of solid component of a silanecompound D (trade name TSL-8185, manufactured by GE Toshiba SiliconesCo., Ltd.) that gives the dynamic friction coefficient of a lens surfaceof 0.48 when applied thereon as a single component, were diluted, andthereby a solution of 0.2% by concentration of solid content wasprepared as a treatment solution for Dip.

A ratio of the dynamic friction coefficients of the silane compound Dand the silane compound C ((the highest value of dynamic frictioncoefficient)/(the lowest value of dynamic friction coefficient)) was5.3.

As for a lens material, a plastic spectacle lens having a layer of hardcoat film and an antireflection coating (the outermost layer is a SiO₂film) (Seiko Super Soverein, manufactured by Seiko Epson Corporation)was prepared and plasma treatment was applied to cleanse a surfacethereof. The plasma treatment was carried out under the conditions oftreatment pressure: 0.1 Torr, introduced gas: dry air, a distancebetween electrodes: 24 cm, output power: DC 1 KV, and a treatment timeperiod: 15 sec.

After taking out of the constant temperature and constant humiditychamber, and followed by cooling, the lens was repeatedly wiped tocleanse with perfluorohexane impregnated-wipe paper (trade name Dusper,manufactured by Ozu Co. Ltd.) until coating unevenness that appears whenbreath was puffed upon the lens disappeared.

(Embodiment 6)

With a vacuum deposition method, on a surface of a plastic spectaclelens (Seiko Super Soverein, manufactured by Seiko Epson Corporation), astain-proofing layer was formed according to a procedure below.

In a fluorine base solvent (trade name Novec HFE-7200, manufactured bySumitomo 3M Co.), 1.86% by concentration of solid component of a silanecompound A (trade name KY-130, manufactured by Shin-Etsu Chemical Co.,Ltd.) that gives the dynamic friction coefficient of a lens surface of0.07 when applied thereon as a single component, and 0.14% byconcentration of solid component of a silane compound B (trade nameKP-801, manufactured by Shin-Etsu Chemical Co., Ltd.) that gives thedynamic friction coefficient of a lens surface of 0.34 when appliedthereon as a single component, were diluted, thereby a solution of 2% byconcentration of solid content was prepared, and porous ceramic pelletswere impregnated with 1 g of this solution.

A ratio of the dynamic friction coefficients of the silane compound Aand the silane compound B ((the highest value of dynamic frictioncoefficient)/(the lowest value of dynamic friction coefficient)) was4.9.

After drying, the pellets were set in a vacuum deposition unit and theunit was evacuated until a pressure of 2 to 3 Pa was attained.

In the next place, in the vacuum deposition unit, a plastic spectaclelens having a layer of hard coat film and an anti-reflection coating(Seiko Super Soverein, manufactured by Seiko Epson Corporation) wasintroduced and the pellets were heated to 400 to 500 degree centigradeto evaporate the silane compounds and thereby to deposit it on a lenssurface. At this time, the pellets were heated by means of a halogenlamp and a deposition time period was set at 7 min. After thedeposition, the inside of the deposition unit was gradually returned toan atmospheric pressure and the lens was taken out, followed by puttingin a constant temperature and constant humidity chamber set at 60 degreecentigrade and 60% RH and by holding there for 2 hr, and thereby astain-proofing layer was formed.

COMPARATIVE EXAMPLE 1

In a fluorine base solvent (trade name Novec HFE-7200, manufactured bySumitomo 3M Co.), a silane compound A (trade name KY-130, manufacturedby Shin-Etsu Chemical Co., Ltd.) that gives the dynamic frictioncoefficient of a lens surface of 0.07 when applied thereon as a singlecomponent was diluted, and thereby a Dip solution of 0.2% byconcentration of solid content was prepared. As for a lens material, aplastic spectacle lens with a layer of hard coat film and ananti-reflection coating (the outermost layer is a SiO₂ film) (SeikoSuper Soverein, manufactured by Seiko Epson Corporation) was preparedand plasma treatment was applied to cleanse a surface thereof. Theplasma treatment was carried out under the conditions of treatmentpressure: 0.1 Torr, introduced gas: dry air, a distance betweenelectrodes: 24 cm, output power: DC 1 KV, and a treatment time period:15 sec.

A plasma-treated lens was immersed in the Dip treatment solution andheld there for 1 min, followed by pulling up at 40 cm/min, furtherfollowed by putting in a constant temperature and constant humiditychamber set at 60 degree centigrade and 60% RH and holding there for 2hr, and thereby a stain-proofing layer was formed.

COMPARATIVE EXAMPLE 2

In perfluorohexane, 0.1% by concentration of solid component of a silanecompound A (trade name KY-130, manufactured by Shin-Etsu Chemical Co.,Ltd.) that gives the dynamic friction coefficient of a lens surface of0.07 when applied thereon as a single component, and 0.1% byconcentration of solid component of a silane compound C (trade nameOptool DSX, manufactured by Daikin Industries Ltd.) that gives thedynamic friction coefficient of a lens surface of 0.09 when appliedthereon as a single component, were diluted, and thereby a solution of0.2% by concentration of solid content was prepared as a treatmentsolution for Dip.

A ratio of the dynamic friction coefficients of the silane compound Aand the silane compound C ((the highest value of the dynamic frictioncoefficient)/(the lowest value of the dynamic friction coefficient)) was1.3.

As for a lens material, a plastic spectacle lens having a layer of hardcoat film and an anti-reflection coating (the outermost layer is a SiO₂film) (Seiko Super Soverein, manufactured by Seiko Epson Corporation)was prepared and plasma treatment was applied to cleanse a surfacethereof. The plasma treatment was carried out under the conditions oftreatment pressure: 0.1 Torr, introduced gas: dry air, a distancebetween electrodes: 24 cm, output power: DC 1 KV, and a treatment timeperiod: 15 sec.

A plasma-treated lens was immersed in the Dip treatment solution andheld there for 1 min, followed by pulling up at 40 cm/min, furtherfollowed by putting in a constant temperature and constant humiditychamber set at 60 degree centigrade and 60% RH and holding there for 2hr, and thereby a stain-proofing layer was formed.

COMPARATIVE EXAMPLE 3

In a fluorine base solvent (trade name Novec HFE-7200, manufactured bySumitomo 3M Co.), 0.04% by concentration of solid component of a silanecompound A (trade name KY-130, manufactured by Shin-Etsu Chemical Co.,Ltd.) that gives the dynamic friction coefficient of a lens surface of0.07 when applied thereon as a single component, and 0.16% byconcentration of solid component of a silane compound B (trade nameKP-801, manufactured by Shin-Etsu Chemical Co., Ltd.) that gives thedynamic friction coefficient of a lens surface of 0.34 when appliedthereon as a single component, were diluted, and thereby a solution of0.2% by concentration of solid content was prepared as a treatmentsolution for Dip.

A ratio of the dynamic friction coefficients of the silane compound Aand the silane compound B ((the highest value of the dynamic frictioncoefficient)/(the lowest value of the dynamic friction coefficient)) was4.9. As for a lens material, a plastic spectacle lens having a layer ofhard coat film and an anti-reflection coating (the outermost layer is aSiO₂ film) (Seiko Super Soverein, manufactured by Seiko EpsonCorporation) was prepared and plasma treatment was applied to cleanse asurface thereof. The plasma treatment was carried out under theconditions of treatment pressure: 0.1 Torr, introduced gas: dry air, adistance between electrodes: 24 cm, output power: DC 1 KV, and atreatment time period: 15 sec.

A plasma-treated lens was immersed in the Dip treatment solution andheld there for 1 min, followed by pulling up at 40 cm/min, furtherfollowed by putting in a constant temperature and constant humiditychamber set at 60 degree centigrade and 60% RH and holding there for 2hr, and thereby a stain-proofing layer was formed.

Evaluation tests below were carried out on thus obtained stain-proofingspectacle lenses. Evaluated results are shown in Table 1.

(1) Measurement of the Dynamic Friction Coefficient

In measuring the dynamic friction coefficient, a digital frictioncoefficient measurement tester (manufactured by Sagawa Seisakusho Co.,Ltd.) was used, and the dynamic friction coefficient between a lens (aplane table lens was used for measuring the dynamic frictioncoefficient) and a cotton cloth was measured. Measurement conditionswere as follows.

-   Vertical load: 600 gf-   Moving speed: 100 mm/min    (2) Axis Deviation Test

Test method: This evaluation was performed by observing whether the axisdeviation, caused by slip between a chuck part (a portion where the lenswas fixed to a shaft of the edging machine) and a surface of the lens,occured or not when a lens was ground into a predetermined frame shapeby use of an edging machine.

Firstly, a test lens was prepared and set to a lens fixing jig. At thistime, in one with an astigmatism index, a astigmatism axis was fixed soas to be in a stipulated direction (for instance, 180°); and in onewithout the astigmatism index, a straight line going through an opticalcenter of the lens was ruled, and this was fixed so as to be in astipulated direction (for instance, 180°). A crab eye type frame, whichis large in an aspect ratio, was prepared and used as a reference frame.

As shown in FIG. 2, a lens 1 was fixed to chucks 2, 3 of an edgingmachine (LE-8080, manufactured by NIDEK Co., Ltd.). The chucks 2, 3pressed the lens so as to clamp the lens from both sides of an opticalaxis of the lens. A tip end of the chuck 2 presses a surface of the lens1 via a lens fixing seal 4.

With the chucks 2, 3 fixed, a grinding stone 5 was used to apply theedging process based on the previous frame data. A lens after finishingthe edging process was inserted into a reference frame and the deviationof the astigmatism axis was measured by use of a lens meter. In the caseof a straight line going through an optical center of the lens beingruled, a deviation angle between the ruled line and a horizontal linegoing through an optical axis of the reference frame was measured.

Twenty lenses were edged and a ratio of ones in which the axis deviationexceeded an allowed range was calculated. The allowed range of the axisdeviation was set at ±2° or less.

(3) Evaluation of Stain-Proofing Performance (Wiping Endurance Test bythe Cotton Cloth)

Test method: A cotton cloth was reciprocated 5000 times on a convexsurface of a lens under load of 200 g. The stain-proofing performanceafter the wiping endurance test was evaluated with a contact angle andthe wiping properties of oily ink.

Evaluation (1): Measurement of Contact Angle

In measurement of the contact angle, a contact angle meter (trade nameCA-D, manufactured by Kyowa Science Co., Ltd.) was used and a watercontact angle was measured by a liquid drop method.

Evaluation (2): Oily Ink Wiping Performance

On a convex surface of a lens, a straight line of substantially 4 cm waswritten with a black oily marking pen (Hi-Mackee Care, manufactured byZebra Co., Ltd.), followed by leaving for substantially 5 min. Afterleaving such a time, the marked portion was wiped with a wipe paper(Kaydry, manufactured by Crecia Corp.) and the easiness of wiping wasevaluated according to criteria below.

◯: completely removed by wiping 10 times or less.

Δ: completely removed by wiping 11 to 20 times.

X: incapable of completely removing even by wiping 20 times.

TABLE 1 Wiping endurance Ratio of Incidence Wiping endurance (wipingdynamic Dynamic rate (contact angle) performance) friction friction ofaxis After After coefficients*¹ coefficient deviation enduranceendurance Overall — — % Initial test Initial test evaluation Embodiment14.9 0.08 0 105 104 ◯ ◯ ◯ Embodiment2 4.9 0.18 0 101 97 ◯ ◯ ◯ Embodiment33.8 0.12 0 106 102 ◯ ◯ ◯ Embodiment4 5.3 0.18 0 101 94 ◯ ◯ ◯ Embodiment55.3 0.15 0 102 99 ◯ ◯ ◯ Embodiment6 4.9 0.08 0 110 104 ◯ ◯ ◯ Comparative— 0.07 90 106 104 ◯ ◯ X Example 1 Comparative 1.3 0.09 95 111 108 ◯ ◯ XExample 2 Comparative 4.9 0.22 0 107 102 Δ ◯ X Example 3 *¹A value of(the highest dynamic friction coefficient)/(the lowest dynamic frictioncoefficient) of surfaces when each of two or more kinds of silanecompounds is formed as a single component.

From the results of Table 1, on each of spectacle lenses (embodiments 1through 6), a stain-proofing layer is formed with two or more kinds ofsilane compounds that are selected so as to be different in the dynamicfriction coefficient after treatment, and includes at least one or morekinds of fluorine-containing silane compounds. When compared theseembodiments 1 through 6 with a spectacle lens (comparative example 1) onwhich a stain-proofing layer is formed only with a fluorine-containingsilane compound that is low in the dynamic friction coefficient whenformed as a single component and can give a lens surface high in theslipperiness, or a spectacle lens (comparative example 2) on which astain-proofing layer is formed, in which a ratio of the highest value ofthe dynamic friction coefficients to the lowest value of the dynamicfriction coefficients is 1.4 times or less, these embodiments 1 through6 are substantially the same in the stain-proofing effect and thedurabilityon one hand and remarkably reduced in the incidence rate ofthe axis deviation on the other hand.

Furthermore, in a spectacle lens (comparative example 3) on which astain-proofing layer is formed from silane compounds in which a contentof a silane compound that is low in the dynamic friction coefficient ofa lens surface when formed as a single component and high in theslipperiness of the lens surface is less than 30% by weight of a totalamount of the silane compounds, the surface slipperiness is lowered toan extent that allows applying the edging process, but thestain-proofing effect intrinsic to the fluorine-containing compound isdeteriorated.

From the above, it is confirmed that a spectacle lens on which astain-proofing layer is formed with two or more kinds of silanecompounds that are selected so as to be different in the dynamicfriction coefficient after treatment and includes at least one or morekinds of fluorine-containing silane compounds, can reduce theslipperiness of a lens surface to an extent that allows applying edgingprocess without deteriorating the stain-proofing effect.

INDUSTRIAL APPLICABILITY

The present invention can be applied to stain-proofing spectacle lenses;however, it is not restricted to the above.

1. A stain-proofing spectacle lens, comprising: a stain-proofing layerformed on a surface of the spectacle lens with two or more kinds ofsilane compounds including at least one or more kinds offluorine-containing silane compounds; wherein dynamic frictioncoefficients of lens surfaces, defined by each of the two or more kindsof silane compounds as a single component, a highest dynamic frictioncoefficient value is 1.4 times or more of a lowest dynamic frictioncoefficient value.
 2. The stain-proofing spectacle lens according toclaim 1: wherein, among two or more kinds of the silane compounds, acontent of a silane compound that gives a surface lowest in the dynamicfriction coefficient is in the range of 30 to 99% by weight relative toa total amount of silane compounds.
 3. The stain-proofing spectacle lensaccording to claim 1: wherein the dynamic friction coefficient of a lenssurface that is formed with a silane compound that gives the lowestdynamic friction coefficient among two or more kinds of silane compoundsas a single component is 0.2 or less.
 4. The stain-proofing spectaclelens according to claim 1: wherein, among two or more kinds of thesilane compounds, at least one kind is expressed with a general formula(1) below

(In the formula, R_(f) expresses a straight chain or a branched chainperfluoroalkyl group having 1 to 16 carbon atoms; X, an iodine atom or ahydrogen atom; Y, a hydrogen atom or a lower alkyl group; Z, a fluorineatom or a trifluoromethyl group; R¹, a hydrolizable group; R², ahydrogen atom or an inactive monovalent organic group; a, b, c and d, aninteger of 0 to 200; e, 0 or 1; m and n each, an integer of 0 to 2; andp, an integer of 1 to 10).
 5. The stain-proofing spectacle lensaccording to any one of claims 1 through 4: wherein an anti-reflectioncoating is formed as for a lower layer of the stain-proofing layer ofthe stain-proofing spectacle lens.
 6. A method of manufacturing astain-proofing spectacle lens, comprising: a step of forming anantireflection coating on a surface of a lens base material on which ahard coat film may be formed; and a step of forming a stain-proofinglayer, from two or more kinds of silane compounds including at least onekind or more of fluorine-containing silane compounds, on theantireflection coating; wherein dynamic friction coefficients of lenssurfaces, defined by each of the two or more kinds of silane compoundsas a single component, a highest dynamic friction coefficient value is1.4 times or more a lowest dynamic friction coefficient value.
 7. Themethod of manufacturing a stain-proofing spectacle lens according toclaim 6, wherein a treatment agent containing the two or more kinds ofthe silane compounds is coated on a lens surface in the step of forminga stain-proofing layer from two or more kinds of silane compoundsincluding at least one or more kinds of fluorine-containing silanecompounds on the antireflection coating.
 8. The method of manufacturinga stain-proofing spectacle lens according to claim 6: wherein two ormore kinds of the silane compounds are evaporated in a vacuum chamberand stuck on a lens surface in the step of forming a stain-proofinglayer from two or more kinds of silane compounds including at least oneor more kinds of fluorine-containing silane compounds on theantireflection coating.